DESCRIPTION: This proposal has been prepared in response to the National Electric and Magnetic Field Health Effects Research Program, National Institute of Environmental Health Sciences, NIH, entitled "Cellular Effects of Low Frequency Electromagnetic Fields," the request for proposal (RFA) ES-94- 001. In particular, the investigators respond to the need for a research effort, which addresses the effects of power- frequency 60 Hz electromagnetic fields on gene expression in human cells. They will test the hypothesis that extremely low frequency (ELF) electro- magnetic field (EMF) action on cells has genetic components associated with cancer. Accordingly, this proposal has two aims: 1) they will provide detailed characterization of the transcriptional response of cultured human cells (HL-60 and MCF-7). In studies proposed for this aim, they will investigate messenger RNA (mRNA) expression of c-myc, c-fos, wild-type p53, wild-type p53-activated fragment 1 (WAF-1) and ornithine decarboxylase (ODC) genes at several patterns of exposure and post- exposure times using Northern blotting and reverse transcriptase- polymerase chain reaction (RT-PCR); and 2) They will study differential gene expression in HL-60 and MCF-7 cells using similar exposure conditions as for aim 1. They have developed a novel technique for rapid screening and isolation of differentially expressed genes. In contrast to differential or subtractive hybridization technique, which preferentially detects genes belonging to the abundant class of genes, their technique can detect genes in both, abundant and scarce classes.This technique is now routinely used to compare genes involved in malignant progression in human esophageal cancer. The proposed studies in aim 1 will include cells, ELF EMF exposure conditions and end points previously investigated and published by others, and will establish their laboratory baseline for the remaining studies.They will use only the established and proven molecular methods as well as an existing ELF EMF exposure system, which has been constructed, characterized, and used in the currently funded research.